Bearing rings in aircraft engines are generally exposed to high rollover loads and high operating temperatures. This applies in particular for bearing rings in bearing systems for main shafts. The materials used for such bearing rings are predominantly heat-resistant, fully hardened or case-hardened steels, such as, for example, M50 (AMS 6491), M50NiL (AMS 6278), RBD, Pyrowear 675 (AMS 5930).
The heat dissipation from the contact areas takes place with the aid of a continuous oil flow. In this case, an improved heat dissipation from the contact area may effectuate an increase in the performance of bearings, for example, in the engine area. A heat dissipation approach is known, for example, from EP 2 503 107 B1 which describes a bearing system for a turbomachine, one bearing housing part being provided with a coolant channel and one bearing housing part being provided with a lubricant channel, the coolant channel and the lubricant channel being fluidically separated from one another. Specifically, a material composite structure made of a bearing housing including integrated cooling channels in combination with a bearing shell is described.
Since the fatigue strength of the aforementioned heat-resistant steels decreases as the temperature increases, however, and the operating temperature, below which the oils used for lubrication and heat dissipation may be used, is limited, a higher temperature in the contact area may not be permitted with the presently utilized bearing materials and oils.
In principle, a heat dissipation from the contact area is also possible, for example, in EP 2 503 107 B1. The cooling capability is limited, however, since the channels through which coolant flows are relatively far removed from the contact surface, since the bearing shell must have a certain minimum thickness, for reasons of strength. Moreover, the manufacture of the described composite structure is problematic. In addition, due to the introduction of the cooling channels on the inner diameter of the inner ring or on the outer diameter of the outer ring, the fit conditions present there, for example in terms of strength and a different expansion of the partners in the fit, are influenced.